Conventionally, a fastener member provided with a base portion that has a surface and a plurality of engaging members that are provided in an upright manner to the surface, wherein the fastener member mechanically couples with a coupling target by engaging the engaging members to the coupling target. One example of this type of technology is disclosed in Japanese Unexamined Patent Application Publication No. H08-112113A, which describes a fastener member provided with protrusions that are provided in a substantially vertically upright protruding manner to roughly a center of a base portion. The fastener member described in Japanese Unexamined Patent Application Publication No. H08-112113A is such that the protrusions are inserted into holes in a target fastener member and thus positioned. When a predetermined amount of pressure is applied thereto in an approximating direction, structurally weak portions of the protrusions are destroyed, causing the protrusions to deform and become engaged to the target fastener member.